ZOOLOGICA. The first recorded earthworms from Burkina Faso with description of a new species (Oligochaeta: Eudrilidae, Acanthodrilidae)

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1 MISCELLANEA To mus 13. ZOOLOGICA 2000 HUNGARICA The first recorded earthworms from Burkina Faso with description of a new species (Oligochaeta: Eudrilidae, Acanthodrilidae) p by Cs. Csuzdi (Received July 5, 1999) Abstract. The first recorded earthworms from Burkina Faso are presented. Besides the species Millsonia inermis (Michaelsen, 1892) and Legonea rapta Sims, 1964 a further earthworm Legonea derouardi sp. nov. is described. Keywords: Burkina Faso, Legonea, new species Introduction The earthworm fauna of West Africa has intensively been investigated since the beginning of this century (Michaelsen 1912, 1914a, b, Omodeo 1955, 1958; Omodeo & Vaillaud 1967; Sims 1965, 1986, Zicsi & Csuzdi 1986, Csuzdi 1995). The investigations were concentrated mainly for historical reasons on the countries of the Golf of Guinea. Almost no earthworm records are present from the inner West-African territories such as Mali, Burkina Faso and Niger notwithstanding that the southernmost parts of these countries possess a similar climate to that of the most investigated lands, Ghana and Ivory Coast. In 1995 I received a small sample of earthworms from a fellow of IRD (Orstom) (Dakar, Senegal), which was collected in Burkina Faso. The material consisted of three species belonging to genera Millsonia (Acanthodrilidae) and Legonea (Eudrilidae). Of the three species M. inermis is widely distributed in Togo and Ghana. Legonea rapta Sims, 1964 was previously known only from the type locality, Jangebunga, south-eastern Ghana and the third one represents a new species. Taxonomy Acanthodrilidae Claus, 1880 Benhamiinae Michaelsen, 1897 Millsonia Beddard, 1894 Millsonia Beddard 1894: 380 Dichogaster (part.): Michaelsen, 1900: 334 Millsonia: Omodeo, 1955: 218; Sims, 1986: 277; Csuzdi, 1996: 360.

2 Millsonia inermis (Michaelsen, 1892) Benhamia inermis Michaelsen, 1892: 209. Dichogaster inermis: Michaelsen, 1900: 366; Michaelsen, 1912: 28; Michaelsen, 1937: 501. Milllsonia inermis: Omodeo, 1958: 59; Sims, 1965: 299; Sims, 1986: 293. Locality: AF/ Ex. Burkina Faso, Sobaka, Koukalanasse, 200 km south from the capital Ouagadougou. Leg. L. Derouard, 16.X Considering that this is the most variable species of the genus Millsonia a short description is given here. External characters. Length mm, diameter 5-7 mm segments, anteriorly triannulate. First dorsal pore 11/12. Clitellum saddle shaped, on segments 1/ Female pores on segment 14 paired, between ab, located somewhat anteriorly to the setal ring. Prostate pores paired, open in the edges of a quadrate-shaped invagination (male field) on Spermathecal pores paired in furrows 7/8-8/9, somewhat lateral to the setal line b. Paired papillae present on the posterior part of segments 9, 10, 11, 15, 16. Unpaired glandular pads mid-ventral, usually on segments Internal characters. Septa 5/6-9/10 greatly thickened, 10/11-11/12 less so. Gizzards in 5. and 6. segments, strongly muscularized and of equal size. Last hearts in 13. Calciferous glands in , the first pair is small. Intestinal caeca 14 pairs, in segments Meronephridia 10 pairs, with a pair of caudal megameronephridia. Racemose vesiculae seminalis present in segments Prostates paired in 17 and 19, highly convoluted. Penial setae absent. Spermathecae in segment 8 and 9; the duct short with numerous sperm-chambers in the wall. Ampulla elongated sac-shaped. Eudrilidae Claus, 1880 Legonea Clausen, 1963 Legonea Clausen, 1963: 301; Sims, 1964: 591. Legonea rapta Sims, 1964: 601. Legonea rapta Sims, 1964 Locality: AF/ Ex. Burkina Faso, Sobaka, Koukalanasse, 200 km south from the capital Ouagadougou. Leg. L. Derouard, 16.X External characters. Length 110 mm, diameter 5 mm, 230 segments. Colour reddishbrown, on dorsal side intensively expressed. Dorsal pores absent. Clitellum annular, on 1/2 14, segments. Male pore single median ventral in intersegmental furrow 17/18 with everted horn-shaped copulatory appendages (Fig. 1). Porophores absent. Female pores on small papillae, paired on the posterior margin of segment 14, in line with the nephridiopores. Spermathecal pore single, on a mid-ventral papilla in intersegmental furrow 12/13. Nephridiopores between setal lines c-d.

Fig. 1. Legonea rapta Sims, 1964 Ventral view of the clitellar segments, st.p = spermathecal pore; ca = copulatory appendages everted Internal characters.

3 Fig. 1. Legonea rapta Sims, 1964 Ventral view of the clitellar segments, st.p = spermathecal pore; ca = copulatory appendages everted Internal characters. Oesophageal gizzard in 5, intestinal gizzards in 19-26, 8 pairs. As septum 13/14 absent, the exact location of the calciferous gland could not be determined. It might equally be in segment 13, as well as in 14. Testes paired in 10 and 11 enclosed in U-shaped sperm-reservoirs. Spermathecal receptaculum single, supra intestinal, circumoesophageal duct (Verbindungsslauch) present. Euprostates paired, flexed into U-form, ectally taper into slender ducts and communicate with the thick penis sheath (Sims, 1964 p. 602, Fig. 5). Remarks: Our specimens conform to the original description, apart from their smaller size and the number of intestinal gizzards. The long distance between the two known localities suggests a wider, but unsampled distribution of this species. Legonea derouardi sp. nov. Locality: Holotype; AF/3805 Burkina Faso, Sobaka, Koukalanasse, 200 km south from the capital Ouagadougou. Leg. L. Derouard, 16.X Paratypes; AF/ Ex. Locality same as that of the holotype.

E x t e r n a l characters. Holotype. Length 85 m m, diameter 4 m m, 171 segments. Paratypes 7 0-9 0 m m in length, 3.5-4 m m in diameter, 176-216 segments. Colour dark violet above, paler below.

4 E x t e r n a l characters. Holotype. Length 85 m m, diameter 4 m m, 171 segments. Paratypes m m in length, m m in diameter, segments. Colour dark violet above, paler below. Prostomium prolobous, dorsal pores absent. Setal arrangement eudriline, on segment 22, aa:ab:bc:cd:dd = 3.7:2.7:3.3:1:1:17 C l i t e l l u m annular, on segments M a l e pore single, median ventral i n intersegmen tal furrow 17/18 (Fig. 2). Porophores absent. Female pores on small papillae, paired on the posterior margin o f segment 14, i n line w i t h the nephridiopores. Spermathecal pore single, on a mid-ventral papilla on the frontal edge o f segment 13. Nephridiopores between setal lines c and d, near anterior margins of the segments. Fig. 2. Legonea derouardi sp. nov. Ventral view of the clitellar segments, pr. p = prostata pore; st.p = spermathecal pore Internal characters. Septa 5/6 muscular, 6/7-11/12 thickened, 13/14 missing. Oesophageal gizzard in 5, intestinal gizzards i n 19-24, 6 pairs. Typhlosole is very small, almost lacking. Unpaired oesophageal glands are present in 9, 10, I L A pair o f calciferous glands located in the fused cavity of segments 13 and 14. Hearts in segments Holonephridial. One pair o f nephridia in each segment, nephridial sac biarmous (Fig. 3). Holoandric. Testes paired in 10 and 11, each enclosed in an ectally convoluted spermreservoir (Fig. 4). Seminal vesicles paired i n 11, 12. Spermathecal system complex. A ringshaped coelomic sac (Verbindungsslauch) w i t h a supra-intestinal diverticulum (Fig. 5) encircles the oesophagus i n the cavity o f segments 13-14, and communicates ventro-medially w i t h the muscular spermathecal atrium. The ovaries are paired and situated laterally to the spermathecal atrium in 13. Each ovarium is enclosed in an ovarian vesicle from w h i c h

5 the ovarian duct passes into an ovisac. The ental part of this ovisac forms a bursa propulsoria, which medially communicates with the ring-shaped coelomic sac, while laterally opens into the female pores on the posterio-lateral part of segment 14 (Fig. 6). Euprostates paired, somewhat flexed, ectally taper into slender ducts and communicate with the ental end of the thick penis sheath, bearing a rounded penial chamber (Fig. 7). Within the penial chamber a pair of small copulatory appendages arises from the ventral surface (Fig. 8). The new species is most closely related to the other penis bearing species; L, rapta Sims, 1964, however differs in the position of the spermathecal pore, the shape of the copulatory appendages, the shape of sperm reservoirs and in size. Fig. 3. Legonea derouardi sp. nov. Nephridial vesicle Fig. 4. Legonea derouardi sp. nov. Sperm reservoir Fig. 5. Legonea derouardi sp. nov. Theco-ovarian system, s = septum 12/13; ov = ovarium; sa = spermathecal atrium; cd = circumoesophageal duct; os = ovisac; bp = bursa propulsoria; am = spermathecal ampulla

6 Fig. 6. Legonea derouardi sp. nov. Posterior male organ, pr = prostata; vd = vas deferens; ps = penial sheath; pc = penial chamber Fig. 7. Legonea derouardi sp. nov. Cross section of the penial chamber, ca = copulatory appendages Fig. 8. Legonea derouardi sp. nov. Spermatechal ampulla

7 Acknowledgements My thanks are due to Mr. Laurent Derouard IRD (Orstom) Bondy-Dakar, for collecting and sending me this small earthworm sample from Burkina Faso. References Beddard, FE. (1894): On two new genera, comprising three new species of earthworms from western tropical Africa. Proc. zool. Soc. Lond. 1894: Clausen, M.W. (1963): Two new genera and three new species of Eudriline earthworms from West- Africa. Vidensk. Meddr Dansk naturhist. Foren 126: Csuzdi, Cs. (1995): Neue und wenig bekannte Regenwürmer aus Senegal und Sierra Leone (Oligochaeta, Acanthodrilidae: Benhamiinae). Opusc. zool. Bpest 27-28: 25^10. Csuzdi, Cs. (1996): Revision der Unterfamilie Benhamiinae Michaelsen, 1897 (Oligochaeta: Acanthodrilidae). Mitt. zool. Mus. Berl. 72: Michaelsen, W. (1892): Terricolen der Berliner Zoologischen Sammlung II. Arch. Naturgesch. 1: Michaelsen, W. (1900): Oligochaeta. Das Tierreich 10: Michaelsen, W. (1912): Oligochäten vom tropischen und südlich-subtropischen Afrika I. Zool. Stuttgart 26: Michaelsen, W. (1914a): Oligochäten vom tropischen Afrika. Mitt. naturh. Mus. Hamb. 31: Michaelsen, W. (1914b): Oligochäten aus dem tropischen Westafrika gesammelt von Prof. Dr. F.Silvestri. Boll. Lab. Zool. gen. agr. Portici9: Michaelsen, W. (1937): On a Collection of African Oligochaeta in the British Museum. Proc. zool. Soc. Lond. 107: Omodeo, P. (1955): Eudrilinae e Octochaetinae della Costa d'avorio (Oligochaeta). Mem. Mus. natn. Verona 4: Omodeo, P. (1958): La reserve naturelle integrale du Mont Nimba. I. Oligochetes. Mem. Inst. fr. Afr. noire 53: Omodeo, P. & Vaillaud, M. (1967): Les oligochetes de la savane Gpakobo en Cote-dTvoire. Bull. Inst. fr. Afr. noire ser. A. 29/3: Sims, R. W. (1964): Internai fertilization and the functional relationship of the female and the spermathecal systems in new earthworms from Ghana (Eudrilidae: Oligochaeta). Proc. zool. Soc. Lond. 143/4: Sims, R. W. (1965): Acanthodrilidae and Eudrilidae (Oligochaeta) from Ghana. Bull. Br. Mus. nat. Hist. (Zool.) 12/8: Sims, R. W. (1986): Revision of the western African earthworm genus Millsonia (Octochaetidae: Oligochaeta) with notes on two new species of the genus Agastrodrilus (Octochaetidae) from Ghana. Bull. Br. Mus. nat. Hist. (Zool.) 50/5: Zicsi, A. & Csuzdi, Cs. (1986): Neue Eminoscolex-Arten aus dem Kongo-Gebiet (Oligochaeta: Eudrilidae). Acta zool. hung. 32(1-2): Author's address: Dr. Csaba Csuzdi Systematic Zoology Research Group of the Hungarian Academy of Sciences at the Department of Systematic Zoology and Ecology, Eötvös Loránd University H-1445 Budapest. Pf. 330, Hungary csuzdi@cerberus.elte.hu

ZOOLOGISCHE MEDEDELINGEN

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